Backplane wire and noise eliminator tube

ABSTRACT

An optical switch for switching data in a network. The switch includes a housing. The switch includes a transmitter receiver means which transmits to or receives from the network the data. The transmitter receiver means is disposed in the housing. The first optical path forms a first closed optical loop along which the data flows in a first direction. The switch includes a second optical path forming a second closed optical loop along which the data flows in a second direction. The second direction is opposite the first direction. The first and second optical paths each having a portion in which the transmitter receiver means is inserted into or removed from the first and second optical paths without disruption of switching of data by the switch. A method for switching data in a network.

FIELD OF THE INVENTION

The present invention is related to the switching of data optically witha switch where input ports and output ports to a network can beintroduced without disruption of the switching operation of the switch.The present invention is related to the switching of data optically witha switch where input ports and output ports to a network can beintroduced without disruption of the switching operation with a firstoptical path and a second optical path transmitting data in a directionopposite to the first optical path.

BACKGROUND OF THE INVENTION

There currently exist too many high speed electrical interconnects in anATM/MPLS switch/router. The electrical interconnects cause noise, thickbackplanes, and expensive sockets that can be eliminated. The presentinvention saves money in regard to how it is built, saves space in thechassis, increases speed without increasing emissions, and is expandableas well as upgradeable.

SUMMARY OF THE INVENTION

The present invention pertains to an optical switch for switching datain a network. The switch comprises a housing. The switch comprises atransmitter receiver means which transmits to or receives from thenetwork the data. The transmitter receiver means is disposed in thehousing. The first optical path forms a first closed optical loop alongwhich the data flows in a first direction. The switch comprises a secondoptical path forming a second closed optical loop along which the dataflows in a second direction. The second direction is opposite the firstdirection. The first and second optical paths each having a portion inwhich the transmitter receiver means is inserted into or removed fromthe first and second optical paths without disruption of switching ofdata by the switch.

The present invention pertains to a method for switching data in anetwork. The method comprises the steps of switching the data with aswitch by flowing the data along a first optical path forming a firstclosed optical loop along which the data flows in a first direction andalong a second optical path forming a second closed optical loop alongwhich the data flows in a second direction, the second direction beingopposite the first direction. There is the step of inserting atransmitter receiver means which transmits to or receives from thenetwork the data into the first optical path and the second optical pathof the switch without disruption of switching of the data by the switch.

The present invention pertains to a switch for directing optical signalsin a telecommunications network. The switch comprises an opticalbackplane having a first optical path along which the optical signalsflow in a first direction and at least a second optical path along whichoptical signals flow in a second direction. The switch comprises Ninterfaces, where N is greater than or equal to 2 and is an integer.Each interface is in optical communication with the network. Eachinterface receives optical signals from and transfers optical signals tothe network. Each interface in optical communication with the first pathand the second path. Each interface sends optical signals it receivesfrom the network onto the first path and the second path. Each interfacetransferring optical signals to the network it receives from the firstpath and the second path.

The present invention pertains to a method for directing the opticalsignals in a telecommunications network. The method comprises the stepsof receiving the optical signals at a first interface of a switch. Thereis the step of sending the optical signals onto a first optical fiber ina first direction and a second optical fiber in a second direction ofthe switch from the first interface There is the step of receiving at asecond interface of the switch the optical signals from the first fiberand the second fiber There is the step of transferring the opticalsignals from the second interface to a desired destination. Preferably,the method includes the steps of removing an optical connector incommunication with the first optical fiber and the second optical fiberfrom a first slot of a chassis of the switch. There is the step ofinserting a third interface into the first slot so it communicates withthe first fiber and the second fiber.

BRIEF DESCRIPTION OF THE DRAWINGS

In the accompanying drawings, the preferred embodiment of the inventionand preferred methods of practicing the invention are illustrated inwhich:

FIG. 1 is a schematic representation of a portion of the first opticalpath and the second optical path having an integral break/lock.

FIGS. 2a and 2 b are schematic representations of the first and secondoptical paths showing springs about the feeds with an integralbreak/lock, or a board printed circuit board assembly in place of theintegral break/lock, respectively.

FIG. 3 is a schematic representation of a portion of the first andsecond optical paths with the printed circuit board assembly replacingthe integral break/lock.

FIG. 4 is a schematic representation of a portion of the first andsecond optical paths showing the printed circuit board assembly beingplaced therein.

FIG. 5 is a schematic representation showing the printed circuit boardassembly interconnect with the first and second optical paths.

FIG. 6 is a schematic representation of the transmitter and receiver ofthe printed circuit board assembly connected to an optical fiber of anoptical path.

FIG. 7 is a schematic representation of an alternative embodiment of theprinted circuit board assembly interconnected with the first and secondoptical paths.

FIG. 8 is a schematic representation of the insertion/extraction ofphotons at different Lambdas with respect to the alternative embodimentregarding an optical path.

FIG. 9 is a schematic representations of an alternative embodiment of aprinted circuit board assembly connection with the first and secondoptical paths.

FIG. 10 is a schematic representation of waveguide ring resonators.

FIG. 11 is a schematic representation of waveguide ring resonators.

FIG. 12 is a schematic representation of a ring with the filterfunctions utilizing the waveguide ring resonators.

DETAILED DESCRIPTION

Referring now to the drawings wherein like reference numerals refer tosimilar or identical parts throughout the several views, and morespecifically to FIGS. 1 and 2 thereof, there is shown an optical switch10 for switching data in a network 12. The switch 10 comprises ahousing, as shown in FIG. 3. The housing can be, for instance, a chassis14. The switch 10 comprises a transmitter receiver means 16 whichtransmits to or receives from the network 12 the data. The transmitterreceiver means 16 is disposed in the housing. The first optical path 18forms a first closed optical loop along which the data flows in a firstdirection 20 The switch 10 comprises a second optical path 22 forming asecond closed optical loop along which the data flows in a seconddirection 24. The second direction 24 is opposite the first direction20. The first and second optical paths 18, 22 each having a portion 26in which the transmitter receiver means 16 is inserted into or removedfrom the first and second optical paths 18, 22 without disruption ofswitching of data by the switch 10.

Preferably, the portion 26 includes hinges/slides and an integralbreak/lock 30 which fits into the hinges/slides. The portion 26preferably includes sides 32 and includes feeds 34 on each side 32 towhich the first and second paths connect. The feeds 34 are movable to bespread apart or closed together to allow the integral break/lock 30 orthe transmitter receiver means 16 to be inserted or removed from thefirst and second optical paths 18, 22.

Preferably, each feed 34 has one of the hinges/slides. Each feed 34preferably has a spring 36 to which it is mounted. The spring 36 isattached to the housing against which the feed 34 is spread and thenforced back. Preferably, the transmitter receiver means 16 includes aprinted circuit board 38 assembly having a transmitter 40 and receiver42 for transmitting and receiving the data.

The board 38 preferably has locator pins 44, as shown in FIG. 4, whichalign the board 38 into proper placement into the housing so thetransmitter 40 and receiver 42 communicate with the first and secondoptical paths 18, 22 and the first and second optical paths 18, 22extend through the board 38. Preferably, the board 38 includesunload/load slides 46 on each side 32 of the board 38 which fit into thehinges/slides on each feed 34. The first optical path 18 preferablyincludes a first optical fiber 48. The second optical path 22 includes asecond optical fiber 50. The board 38 includes a first optical fibersegment 52 and a second optical fiber segment 54 which align with thefirst optical fiber 48 and the second optical fiber 50, respectively,when the board 38 is in place in the housing, and the integralbreak/lock 30 has a third optical fiber segment 56 and a fourth opticalfiber segment 58 which aligns with the first optical fiber 48 and thesecond optical fiber 50, respectively, when the integral break/lock 30is in place in the housing.

Preferably, the switch 10 includes an optical gel 72 placed atconnection points between the first optical fiber 48 and the firstoptical fiber segment 52 and the second optical fiber 50 and the secondoptical fiber segment 54. Preferably, the board 38 includes a fibermirror 60 and the transmitter 40 includes a laser 62 driver and a fiberdrive 64 connected to the fiber mirror 60 and the laser 62, as shown inFIGS. 5 and 6. The board 38 preferably includes a frequency filter 66connected to the receiver 42 and a fiber drop 68 connected to thefrequency filter 66 and the mirror 60. Preferably, the board 38 includesa frequency control 70 connected to the laser 62.

The present invention pertains to a method for switching data in anetwork 12. The method comprises the steps of switching the data with aswitch 10 by flowing the data along a first optical path 18 forming afirst closed optical loop along which the data flows in a firstdirection 20 and along a second optical path 22 forming a second closedoptical loop along which the data flows in a second direction 24, thesecond direction 24 being opposite the first direction 20, as shown inFIGS. 1-3. There is the step of inserting a transmitter receiver means16 which transmits to or receives from the network 12 the data into thefirst optical path 18 and the second optical path 22 of the switch 10without disruption of switching of the data by the switch 10.

Preferably, the step of inserting includes the step of inserting thetransmitter receiver means 16 along hinges/slides into the first andsecond optical paths 18, 22. There is preferably the step of removing anintegral break/lock 30 from the first and second optical paths 18, 22along the hinges/slides in which the integral break/lock 30 fits.Preferably, there is the step of the spreading apart movable feeds 34having the hinges/slides and the first and second paths to allow theintegral break/lock 30 or the transmitter receiver means 16 to beinserted or removed from the first and second optical paths 18, 22. Thespreading step preferably includes the step of moving the feeds 34 apartagain springs 36 connected to a housing of the switch 10 and the feeds34. Preferably, there is the step of releasing the feeds 34 against thetransmitter receiver means 16 which are held against the transmitterreceiver means 16 by the springs 36.

There is preferably the step of fitting an unload/load slide 46 disposedon each side 32 of a printed circuit board 38 assembly into thehinge/slide 28 on each feed 34. Preferably, as shown in FIG. 4, there isthe step of aligning locator pins 44 of the board 38 with alignmentholes in the housing for proper placement of the board 38 into thehousing so a transmitter 40 and a receiver 42 of the board 38 cancommunicate with the first and second optical paths 18, 22 and the firstand second optical paths 18, 22 extend through the board 38, thetransmitter 40 and receiver 42 for transmitting and receiving the data,respectively.

The aligning step preferably includes the step of aligning a firstoptical fiber 48 of the first path and a second optical fiber 50 of thesecond path with a first optical fiber segment 52 of the board 38 and asecond optical fiber segment 54 of the board 38, respectively.Preferably, there is the step of placing an optical gel 72 at connectionpoints between the first optical fiber 48 and the second optical fibersegment 54, and the second optical fiber 50 and the second optical fibersegment 54.

The present invention pertains to a switch 10 for directing opticalsignals in a telecommunications network 12, as shown in FIGS. 1-3. Theswitch 10 comprises an optical backplane 11 having a first optical path18 along which the optical signals flow in a first direction 20 and atleast a second optical path 22 along which optical signals flow in asecond direction 24. The switch 10 comprises N interfaces, where N isgreater than or equal to 2 and is an integer. Each interface is inoptical communication with the network 12. Each interface receivesoptical signals from and transfers optical signals to the network 12.Each interface in optical communication with the first path and thesecond path. Each interface sends optical signals it receives from thenetwork 12 onto the first path and the second path. Each interfacetransferring optical signals to the network 12 it receives from thefirst path and the second path. An interface can be, for instance aprinted circuit board 38 assembly.

Preferably, the first path forms a closed continuous loop and the secondpath forms a closed continuous loop. The first path preferably includesa first optical fiber 48 and the second path includes a second opticalfiber 50. Preferably, the switch 10 includes optical connectors throughwhich optical signals from the first fiber and the second fiber can flowand a chassis 14 having slots in which the interfaces are held or inwhich the connectors are held if there is no interface. The opticalconnector can be, for instance an integral break/lock 30. The Ninterfaces include a first interface in communication with the firstfiber and the second fiber, and a second interface in communication withthe first fiber and the second fiber.

The switch 10 preferably includes a first optical connector, a firstslot and a third interface which fits into the first slot that the firstoptical connector fits in until it is removed so the third interface andcommunicates with the first fiber and the second fiber. The first pathpreferably includes a power supply attached to the chassis 14 and inelectrical connection to each slot. The power supply powers the first,second and third interfaces when the first, second and third interfacesare fitted in the respective slots. The first interface passes theoptical signals on the first fiber and the second fiber that is notdirected to it onto the other interfaces fitted in the chassis 14.Preferably, the third interface has an ID which it sends along the firstfiber and the second fiber to the first and second interfaces fitted tothe chassis 14 so the first and second interfaces can identify the thirdinterface, and the third interface receives the IDs of the first andsecond interfaces. Preferably, if the first fiber fails, the opticalsignals will still reach the desired interface through the second fiber.

Each interface preferably includes a multichannel optical receiver 42for receiving optical signals from the network 12, and a multichanneloptical transmitter 40 for transmitting optical signals to the network12, a channel tuned receiver 42 for receiving optical signals from thefirst and second fibers, a channel tuned transmitter 40 for sendingoptical signals to the first and second fibers, a multiplexer incommunication with the channel tuned transmitter 40 for multiplexingoptical signals from the channel tuned transmitter 40 to the first andsecond fibers, and a demultiplexer in communication with the channeltuned receiver 42 for demultiplexing digital signals from the first andsecond fibers. Preferably, the multi-channel optical receiver 42determines a destination address for the optical signals it receives andsends the optical signals to an appropriate channel of the channel tunedtransmitter 40 to be transferred to the first and second fibers.

The present invention pertains to a method for directing the opticalsignals in a telecommunications network 12. The method comprises thesteps of receiving the optical signals at a first interface of a switch10. There is the step of sending the optical signals onto a firstoptical fiber 48 in a first direction 20 and a second optical fiber 50in a second direction 24 of the switch 10 from the first interface.There is the step of receiving at a second interface of the switch 10the optical signals from the first fiber and the second fiber There isthe step of transferring the optical signals from the second interfaceto a desired destination. Preferably, the method includes the steps ofremoving an optical connector in communication with the first opticalfiber 48 and the second optical fiber 50 from a first slot of a chassis14 of the switch 10. There is the step of inserting a third interfaceinto the first slot so it communicates with the first fiber and thesecond fiber.

The method preferably includes the step of sending an ID of the thirdinterface from the third interface onto the first fiber and the secondfiber to the first interface and the second interface fitted to thechassis 14 so the first interface and the second interface can identifythe third interface and send the optical signals to the third interfacethrough the first fiber and the second fiber. Preferably, the method asdescribed in claim 13 including the step of sending an ID of the firstinterface and an ID of the second interface from the first interface andthe second interface, respectively, onto the first fiber and the secondfiber to the third interface so the third interface can identify thefirst interface and the second interface and send optical signals to thefirst interface and the second interface.

The method preferably includes the step of receiving optical signals bythe first interface sent by the third interface from the first fibereven though the second fiber has failed. Preferably, the method isdescribed in claim 15 including the steps of determining by a multichannel optical receiver 42 of the first interface the destinationaddress for the optical signals the first interface has received fromthe network 12; and sending the optical signals to an appropriatechannel of a channel tuned transmitter 40 of the first interface to betransferred to the first fiber and second fiber.

In the operation of the invention, FIG. 1 shows a link having a firstoptical fiber 48 and at least a second optical fiber 50. The path of theoptical signal in the fibers may not be traveling in the same direction.The hinges/slides are set up in such a way as to allow the integralbreak/lock 30 to be moved. When a new transmitter 40 receiver 42 board38 is to be added to the switch 10, the integral break/lock 30 is movedto the rear or off of the optical paths so the transmitter 40 receiver42 board 38 can fit into the optical paths of the switch 10, as shown inFIGS. 2 and 3.

This is accomplished by the feeds 34 being spread apart and the linkslid away from the into integral break/lock 30 so the integralbreak/lock 30 can be separated from the optical paths and removed. Thetransmitter 40 receiver 42 board 38 is then positioned into the opticalpaths where the integral break/lock 30 had been disposed. When thetransmitter 40 receiver 42 board 38 is properly in position, the feeds34 are released and moved back into place from the force of springs 36against which they have pressed when they were separated from theintegral break/lock 30. The springs 36 are positioned about the opticalpaths attached to the feeds 34 and submit and to the housing of switch10.

The surfaces of the ends of the optical fibers of the optical paths andthe surfaces of the ends of the optical path segments of the board 38are ground to be an conformance with each other by preferably beingformed into opposing angles so that together they form a continuouswhole fiber, respectively, to ensure proper contact and connection.Preferably, optical gel 72 is placed on the surfaces of the ends of theoptical fibers and optical fiber segments to more completely couple themtogether for minimal loss of the optical signals passing therebetween.

Locator pins 44 align the board 38 for insertion into the optical paths,as shown in FIG. 4. Load/unload slides on each side 32 of the board 38,are aligned with the hinge/slide 28 on each feed 34. The locator pins 44along with the unload/load slides 46 on the side 32 of the board 38,when positioned with the respective hinge/slide 28 cause the transmitter40 receiver 42 board 38 to be guided into proper position and held inplace in the optical paths. To facilitate this movement, prongsconnected to each side 32 of the unload/load slide 46 are squeezedtoward each other to compress slightly the unload/load slides 46 to makeit easier for the board 38 to move into place in the hinges/slides. Whenthe board 38 is properly positioned, the prongs are released, allowingthe unload/load slides 46 to expand into the hinges/slides and be heldthere.

Before inserting the board 38, a polisher board 38 can be inserted intoand then removed from the optical paths so any dust is removed by thepolisher boards 38 from the optical paths where the integral break/lock30 was positioned. This is commonly done if the integral break/lock 30has been positioned in the optical path for over a given period, such asone month. When the boards 38 are shipped to the switch 10, they areshipped with a seal over the fiber interconnects to protect them. Theseal is removed before the insertion of the transmitter 40 receiver 42board 38 into the optical paths, which protects against contamination.Once inserted, the transmitter 40 receiver 42 board 38 immediatelybegins an internal check out including testing that the opticalinterfaces have been properly formed.

The transmitter 40 receiver 42 board 38 has a tunable laser 62 whichtransmits the data that has been received by the board 38 from anexternal source, such as the network 12, as shown in FIGS. 5 and 6.There is a Lambda control on the board 38 connected to the tunable laser62 which controls the frequency at which the data is sent onto the firstoptical fiber 48. Each connection has a unique frequency at which itsdata of the connection is sent along the first optical fiber 48. Thetunable laser 62 is connected to a fiber drive 64 which takes the signalfrom the laser 62 and places it into a form so that it can flow alongthe first optical fiber 48, as is well-known in the art. The fiber drive64 is connected to a fiber mirror 60 which couples the data from thefiber drive 64, as well known who in the art.

The fiber mirror 60 also serves to couple the data flowing along thefirst optical fiber 48 to the transmitter 40 receiver 42 board 38, as iswell-known in the art. The data flowing along the first optical fiber 48at all the various frequencies corresponding to the various connectionsbeing switched by the switch 10, is reflected by the mirror 60 onto afiber drop 68, as is well known in the art. The fiber drop 68 isconnected to a Lambda filter 66 which breaks out the data correspondingto its frequency so that all the connections that are to be received andprocessed by the transmitter 40 receiver 42 board 38 can be processed bya receiver 42 of the transmitter 40 receiver 42 board 38. The Lambdafilter 66 is connected to the receiver 42 on the board 38 which takesthe data and processes it for the next stage of its journey. This nextstage can be storage until an output port on the board 38 to the network12 is available for the transmission of the data to the network 12, orthe elimination of the data since it does not correspond to connectionsthat are to be processed by the board 38.

The transmitter 40 receiver 42 board 38 has an identical structure andoperation in regard to the second optical fiber 50 and the transmissionand reception of data with respect to the second optical fiber 50.

In an alternative embodiment, as shown in FIGS. 7 and 8, there is a conewhich is an optical waveguide, that is disposed in the first opticalfiber segment 52, and another cone disposed in the second optical fibersegment 54. The cone is fabricated with the optical fiber segment. Thereceiver 42 and the transmitter 40 of the board 38 is directly coupledto the cone to receive or transmit photons at different lambdas from orto the respective optical fiber segment. As the photons of the differentLambdas travel along the respective optical fiber segment and passthrough the cone, a portion 26 will also reflect in the cone down to thereceiver 42 of the board 38, as described above, and be processed.Similarly, photons produced by the laser 62 driver are transmitted intothe cone where they reflect along the cone across the respective opticalfiber segments. As they reflect along the cone along the respectiveoptical fiber segment, a portion 26 also refracts through the cone intothe respective optical fibers segment, where it flows along therespective optical path. The photons are introduced into or extractedfrom the cone at about a 15 degree angle for the above to occur. Asexplained, the transmitter 40 and receiver 42 of the board 38 can bedirectly coupled to the cone, or the transmitter 40 and receiver 42 canbe fiber linked to the cone for the photons to be introduced to orextracted from or to the cone.

The switch 10 includes a multi-channel optical receiver(s) 42,multi-channel transmitter 40, de-multiplexer, channel tuned receiver(s)42, channel tuned transmitter(s) 40, optical fiber, auto-mechanicaloptical connector, multiplexer. The transmitter 40 and receiver 42 rideon a board 38 and receive optical information in a similar manner to theadd drop multiplexer in a PMA32 system. This is a much smallerapplication and does not require the high power lasers 62 or controlused in the ADM and transponders involved with the PMA32.

When an interface card is plugged into a location in the chassis/rack,it makes electrical contact and opens the pass-through optical connectorat the backplane 11 side 32 of the board 38. It powers up and continuesto pass the information that is not directed to it on to the other cardsin the chassis/rack.

There is no interruption in service as the backplane 11 optics are twofibers with data traveling in opposite directions. During the seatingand power up operation, the net, to accomplish its task, uses alternatepaths.

The card then initializes by sending its information and ID across theinternal net for the other interface (port) boards 38 to identify. Atthe same time, the inserted board 38 acquires the ID and necessary codeto access the other boards 38.

When data arrives, it gives up a destination address that isinterrupted, sent to the I/O area and an appropriate channel of thelaser 62 and then the data is sent along the optical fibers.

In an alternative embodiment of the interboard connection, and as shownin FIG. 9, the integral break/lock 30 has no length. The feeds 34connect to each other through the integral break/lock 30, and slideapart, as explained above.

Waveguide ring resonators can be used to insert and extract a desiredfrequency, or lambda, into the first and second fibers.

Referring to FIGS. 10-12, on the input is all of the lambdas that are onthe fiber. The target channel or lambda is set by a tunable laser on theextraction ring. The signal is injected at the extraction in theopposite phase of the lambda on the input resulting in elimination ofthe signal on the express out. At the junction of the 2 rings, thephases are in harmony resulting in a signal of the target lambda on thedrop line. For insertion, since there is no lambda on the first andsecond fibers that notches the lambda being inserted, the lambda isinserted directly at the input or at the extraction, and thus present onthe express out. See U.S. patent application Ser. No. 09/734,495,incorporated by reference herein, for a more complete description of theinsertion and extraction of a lambda.

The waveguide ring resonators are suitable for use as two port and threeport filters. The bandwidth can be less than a fixed filter it thefilter can track laser wavelength. With the waveguide ring resonators.

Waveguide ring resonators

thermal or electro-optic tuning, turns off resonant filtering effectduring tuning of filter

only one filter required for each wavelength to be dropped (i.e. n, notm filters)

There can alternatively be used MEMs multiple Fabry-Perot cavity thatoffer:

electrostatic tuning, turns off resonant filtering effect during tuningof filter

only one filter required for each wavelength to be dropped (i.e. n, notm filters)

There can alternatively be used Vernier FBGs (two port only) that offer:

mechanical tuning, grating mismatch during tuning

needs two gratings and two FBGS, so lossy device

only one filter required for each wavelength to be dropped (i.e. n, notm filters)

suppliers: CiDra

The MEMs and FBGs are well known to one skilled in the art.

Although the invention has been described in detail in the foregoingembodiments for the purpose of illustration, it is to be understood thatsuch detail is solely for that purpose and that variations can be madetherein by those skilled in the art without departing from the spiritand scope of the invention except as it may be described by thefollowing claims.

What is claimed is:
 1. A switch for directing optical signals in atelecommunications network comprising: an optical backplane having afirst optical path along which the optical signals flow in a firstdirection and at least a second optical path along which optical signalsflow in a second direction, the first path forms a closed continuousloop and the second path forms a closed continuous loop, the first pathincludes a first optical fiber and the second path includes a secondoptical fiber; N interfaces, where N is greater than or equal to 2 andis an integer, each interface in optical communication with the network,each interface receiving optical signals from and transferring opticalsignals to the network, each interface in optical communication with thefirst path and the second path, each interface sending optical signalsit receives from the network onto the first path and the second path,each interface transferring optical signals to the network it receivesfrom the first path and the second path; and optical connectors throughwhich optical signals from the first fiber and the second fiber can flowand a chassis having slots in which the interfaces are held or in whichthe connectors are held if there is no interface, and wherein the Ninterfaces include a first interface in communication with the firstfiber and the second fiber, and a second interface in communication withthe first fiber and the second fiber.
 2. A switch as described in claim1 including a first optical connector, a first slot and a thirdinterface which fits into the first slot that the first opticalconnector fits in until it is removed so the third interface andcommunicates with the first fiber and the second fiber.
 3. A switch asdescribed in claim 2 including a power supply attached to the chassisand in electrical connection to each slot, the power supply powering thefirst, second and third interfaces when the first, second and thirdinterfaces are fitted in the respective slots, the first interfacepassing the optical signals on the first fiber and the second fiber thatis not directed to it onto the other interfaces fitted in the chassis.4. A switch as described in claim 3 wherein the third interface has anID which it sends along the first fiber and the second fiber to thefirst and second interfaces fitted to the chassis so the first andsecond interfaces can identify the third interface, and the thirdinterface receives the IDs of the first and second interfaces.
 5. Aswitch as described in claim 4 wherein if the first fiber fails, theoptical signals will still reach the desired interface through thesecond fiber.
 6. A switch as described in claim 5 wherein each cardincludes a multichannel optical receiver for receiving optical signalsfrom the network, and a multichannel optical transmitter fortransmitting optical signals to the network, a channel tuned receiverfor receiving optical signals from the first and second fibers, achannel tuned transmitter for sending optical signals to the first andsecond fibers, a multiplexer in communication with the channel tunedtransmitter for multiplexing optical signals from the channel tunedtransmitter to the first and second fibers, and a demultiplexer incommunication with the channel tuned receiver for demultiplexing digitalsignals from the first and second fibers.
 7. A switch as described inclaim 6 wherein the multi-channel optical receiver determines adestination address for the optical signals it receives and sends theoptical signals to an appropriate channel of the channel tunedtransmitter to be transferred to the first and second fibers.
 8. Amethod for directing the optical signals in a telecommunications networkcomprising the steps of: receiving the optical signals at a firstinterface of a switch; sending the optical signals onto a first opticalfiber in a first direction and a second optical fiber in a seconddirection of the switch from the first interface; receiving at a secondinterface of the switch the optical signals from the first fiber and thesecond fiber; transferring the optical signals from the second interfaceto a desired destination; removing an optical connector in communicationwith the first optical fiber and the second optical fiber from a firstslot of a chassis of the switch; and inserting a third interface intothe first slot so it communicates with the first fiber and the secondfiber.
 9. A method as described in claim 8 including the step of sendingan ID of the third interface from the third interface onto the firstfiber and the second fiber to the first interface and the secondinterface fitted to the chassis so the first interface and the secondinterface can identify the third interface and send the optical signalsto the third interface through the first fiber and the second fiber. 10.A method as described in claim 9 including the step of sending an ID ofthe first interface and an ID of the second interface from the firstinterface and the second interface, respectively, onto the first fiberand the second fiber to the third interface so the third interface canidentify the first interface and the second interface and send opticalsignals to the first interface and the second interface.
 11. A method asdescribed in claim 10 including the step of receiving optical signals bythe first interface sent by the third interface from the first fibereven though the second fiber has failed.
 12. A method as described inclaim 11 including the steps of determining by a multi-channel opticalreceiver of the first interface the destination address for the opticalsignals the first interface has received from the network; and sendingthe optical signals to an appropriate channel of a channel tunedtransmitter of the first interface to be transferred to the first fiberand second fiber.
 13. A method for directing optical signals in atelecommunications network comprising the steps of: receiving opticalsignals from the network at N interfaces, where N is greater than orequal to 2 and is an integer, each interface in optical communicationwith the network; sending optical signals from each interface that eachinterface receives from the network onto a first optical path and asecond optical path of an optical backplane; flowing the optical signalsalong the first optical path in a first direction and along at least thesecond optical path in a second direction opposite the first direction,each interface in optical communication with the first path and thesecond path; transferring optical signals to the network from eachinterface that each interface receives from the first path and thesecond path; removing an optical connector in communication with thefirst optical path and the second optical path from a first slot of achassis; and inserting a third interface into the first slot so itcommunicates with the first fiber and the second fiber.